Poppet valves are characterized by having a movable element (the poppet) that is used to direct the flow of a fluid through a valve body. A poppet valve may be used as a check valve in a system that requires flow of a fluid in a single direction. Exemplary systems that may use a poppet valve as a check valve include, without limitation, air compressors and controllers, water treatment facilities, utility facilities, and vehicle fuel systems, such as aircraft fuel systems.
In the operation of an aircraft fuel system, operational fluid that is supplied to the controls may vary in temperature and pressure. To supply fluid to the system, a nozzle engages the poppet and moves it to an open position, thereby opening a fluid passage. Where the internal fluid pressure is greater, the nozzle must exert a greater force to move the poppet to an open position.